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 A058118 Triangle: self-converse semigroups of order n with k idempotents. 4
 1, 2, 1, 5, 5, 2, 18, 24, 16, 6, 93, 123, 112, 58, 19, 930, 754, 764, 542, 254, 68, 22899, 6721, 5567, 4751, 2933, 1214, 285, 1937266, 123988, 49969, 41939, 31392, 17396, 6513, 1376, 613365656, 8265721, 739317, 410158, 328937, 223226, 113160, 38979, 7510 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Andreas Distler, Classification and Enumeration of Finite Semigroups, A Thesis Submitted for the Degree of PhD, University of St Andrews (2010). EXAMPLE 1; 2,1; 5,5,2; 18,24,16,6; 93,123,112,58,19; ... CROSSREFS Row sums give A029851. Main diagonal: A058122. Columns 1-3: A058119-A058121. Sequence in context: A118244 A108410 A058116 * A124226 A248797 A193536 Adjacent sequences:  A058115 A058116 A058117 * A058119 A058120 A058121 KEYWORD nonn,tabl,hard AUTHOR Christian G. Bower, Nov 10 2000 EXTENSIONS More terms from Andreas Distler, Jan 13 2011 STATUS approved

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Last modified October 19 05:01 EDT 2018. Contains 316336 sequences. (Running on oeis4.)